Inherited Immunodeficiencies

Question 1

Asplenia

Answer 1

Affected Gene: Not known
Immune defect: Absence of spleen
Susceptibility: Encapsulated extracellular bacteria

Question 2

C3 deficiency

Answer 2

Affected Gene: C3
Immune defect: Lack of C3
Susceptibility: Recurrent infection with Gram(-) bacteria

Question 3

Factor 1 deficiency

Answer 3

Affected Gene: CF1
Immune defect: Absence of factor 1 and depletion of C3
Susceptibility: Encapsulated bacteria

Question 4

Deficiencies of C5, C6, C7, C8, C9

Answer 4

Affected Gene: C5, C6, C7, C8, C9
Immune defect: Lack of complement-mediated lysis
Susceptibility: Infections due to Neisseria species

Question 5

Paroxysmal nocturnal hemoglobinuria

Answer 5

Affected Gene: Somatic and germline mutations in genes involved in phosphatidylinositol biosynthesis
Immune defect: Lack of complement-regulatory proteins DAF, HRF, CD59
Susceptibility: Lysis of erythrocytes by complement

Question 6

NEMO deficiency(X-linked)

Answer 6

Affected Gene: IKBKG(NEMO, inhibitor of kB kinase gamma)
Immune defect: Impaired activation of NFkB
Susceptibility: Chronic bacterial and viral infections; developmental defects

Question 7

Chronic granulomatous disease

Answer 7

Affected Gene: NOX1(NADPH oxidase)
Immune defect: Impaired neutrophil function
Susceptibility: Chronic bacterial and fungal infections

Question 8

MBL deficiency

Answer 8

Affected Gene: MBL(mannose-binding lectin)
Immune defect: Lack of mannose-binding lectin
Susceptibility: Meningitis due to Neisseria meningitidis

Question 9

NK-cell deficiency

Answer 9

Affected Gene: GATA2
Immune defect: Absence of NK cells
Susceptibility: Herpesvirus infections

Question 10

Hyper-IgM deficiency

Answer 10

Affected Gene: Activation induced cytidine deaminase(AICDA) or CD40 ligand(CD40LG), or CD40, or IKBKG
Immune defect: No isotype switching or somatic hypermutation in B cells
Susceptibility: Extracellular bacterial and fungal infections

Question 11

IgG2 deficiency

Answer 11

Affected Gene: Not known
Immune defect: Lack of IgG2
Susceptibility: Encapsulated bacteria

Question 12

SCID

Answer 12

Affected Gene: Various
Immune defect: Absence of B-cell and T-cell function
Susceptibility: All types of infection

Question 13

Omenn syndrome

Answer 13

Affected Gene: RAG1 or RAG2 or Artermis
Immune defect: Impaired V(D)J recombination
Susceptibility: All types of infection

Question 14

MHC Class 1 deficiency(Bare lymphocyte syndrome type 1)

Answer 14

Affected Gene: TAP1 or TAP2
Immune defect: Low MHC class 1 expression
Susceptibility: Respiratory virus infections

Question 15

Pre-B-cell receptor deficiency

Answer 15

Affected Gene: IGLL1(delta5)
Immune defect: Lack of B cells and antibodies
Susceptibility: Persistent bacterial infections

Question 16

X-linked-agammaglobulinemia

Answer 16

Affected Gene: BTK(bruton tyrosine kinase)
Immune defect: B cells blocked at pro-B cell stage
Susceptibility: Recurrent bacterial infections

Question 17

Complete DiGeorge syndrome

Answer 17

Affected Gene: Not known
Immune defect: Absence of thymus and T cells
Susceptibility: All types of infection

Question 18

APECED

Autoimmune poly-endocrinopathy-cadidiasis-ectodermal dystrophy

Answer 18

Affected Gene: AIRE(autoimmune regulator)
Immune defect: Reduced T-cell tolerance to self antigens
Susceptibility: Autoimmune disease

Question 19

ZAP-70 deficiency

Answer 19

Affected Gene: ZAP70
Immune defect: T cells that cannot signal through their antigen receptors
Susceptibility: All types of infection

Question 20

C4A or C4B

Answer 20

Affected Gene: C4A, C4B
Immune defect: Impaired clearance of immune complexes
Susceptibility: Autoimmune disease and infections

Question 21

Selective IgA deficiency

Answer 21

Affected Gene: Not known
Immune defect: Lack of IgA
Susceptibility: No major susceptibility

Question 22

SCID with ADA deficiency results in

Answer 22

No T or B cells, general susceptibility

Question 23

SCID with PNP deficiency results in

Answer 23

No T or B cells, general susceptibility

Question 24

SCID with X-linked scid

Answer 24

No T cells, general susceptibility, bubble boy

Question 25

SCID with autosomal scid

Answer 25

No T or B cells, general susceptibility

Question 26

MHC class II deficiency

Answer 26

• lack of expression of MHC II
• No CD4 T cells
• general susceptibility